#include <iostream>
#include <vector>

using namespace std;
class Solution
{
public:
    int trailingZeroes(int n)
    {
        int ans = 0;
        while (n)
        {
            n /= 5;
            ans += n;
        }
        return ans;
    }
};

int main()
{
    Solution s;
    cout << s.trailingZeroes(10) << endl;
    return 0;
}